1955 Rolls-Royce Silver Dawn

Both the Rolls-Royce and Bentley vehicles wore coach built-bodies during the pre-World War II era. When peacetime resumed, both would offer a factory-built body for the first time, with Bentley's model called the Mark VI and Rolls-Royce's the Silver Dawn. The Bentley Mark VI arrived on the market first, in 1946, and 5,208 examples were built by the time production ended in 1952. The Rolls-Royce Silver Dawn followed in 1949, and 760 were built by 1955.

The 'factory' Rolls-Royce and Bentley bodies were built by the Pressed Steel Company of England. Both models had a 120-inch wheelbase, were approximately 70 inches wide, and had a standard length of 192 inches. The Silver Dqwn was available in three different wheelbase lengths ranging from 192- to 210 inches. The Bentley stood 64.5 inches tall, and the Rolls-Royces at 69 inches. The Bentley was initially powered by a 4.3-liter F-head straight-6, later growing to 4.6 liters in 1951. The Rolls-Royce used a 4.2-liter engine, upgrading to a 4.6-liter unit in 1951. A high-compression cylinder head was fitted beginning in 1953.

Most of the Silver Dawn vehicles wore factory-built standard steel bodies supplied by the Pressed Steel Company Limited, plus sixty-four with coachbuilder bodies. Of the 761 (as few as 760) examples of the Silver Dawn built, 591 were powered by the 4.5-liter engine. Silver Dawn Series A through D had coachwork identical to the Mark IV. The 'E' Series Silver Dawn arrived in mid-1952 with an enlarged boot, changes to the rear wings, updates to the suspension, and an optional four-speed automatic transmission. The final series was the 'J' Series.

The Silver Dawn was an 'export only' model initially unavailable in Britain's home market until 1953. Introduced in 1949 at the Canadian International World's Fair in Toronto (another first for the marque), it had a separate chassis, an independent front suspension, hydraulic front brakes, and mechanical rear brakes with mechanical servo assist. Helical springs and hydraulic dampers were at the front, and in the back were semi-elliptic springs with hydraulic dampers. The transmission was a four-speed manual with column or floor level controls, with synchromesh in the 2nd through 4th gear. A four-speed automatic transmission was available from late 1952 on the 'E' Series chassis. The steering was by a cam and roller follower system.

The 4,257cc six-cylinder engine had an inlet-over-exhaust valve gear that had been in development since the mid-1930s. A belt drive was used for the water pump and dynamo for the first time on this engine, and a Zenith Stromberg carburetor in Rolls-Royce configuration. It had a cast iron block, an aluminum alloy head, seven main bearings, and solid valve lifters. Displacement grew to 4,566cc in 1951, and the previous carburetors were exchanged for twin SUs from the Mark VI.

by Daniel Vaughan | May 2023